Hi, I would like to cancel and remove all Data from this app

I'll help you with removing your data, Paulo1.

If you're a new customer, you can easily start over. You can reset your account that has not been active for more than 90 days by purging it. This process will delete all data in the company file. You can no longer restore it once it's deleted. 

You can purge the file when you open QuickBooks Online through the browser. Here's how:

1. Log in to QuickBooks Online.
2. Change the URL that will include /purgecompany (Example: https://sg.qbo.intuit.com/app/purgecompany).
3. The next page will provide the items' summary to delete. Enter Yes to delete the data, then click OK. 

When you open your QBO app, the data will be removed. 

If your account is more than 90 days old, you're unable to remove the data. You'll have to cancel the account instead, then start a new subscription. 

If you have other concerns, feel free to drop a comment below.